Morphology and anatomy of rhizome and root structures in seven Pteris L. species (Pteridaceae) from Southwestern Nigeria

Abstract

Morphological and anatomical structures of seven Pteris species from various locations in Southwestern Nigeria were examined. This study aimed to affirm the affinities and relevance of rhizome and root structures within the genus Pteris. Mature healthy plants of each species were collected, and morphological observations of rhizomes and roots were documented for each species. The transverse sections of rhizomes were prepared by cutting at 10 µm thickness using Reichert Sliding Microtome while roots were embedded through standard procedures. The results showed that morphologically, rhizomes in P. acanthoneura, P. atrovirens, P. mildbraedii, P. togoensis and P. similis were erect to sub erect, but rhizomes were short creeping in P. ensiformis and P. vittata. The anatomy of the rhizomes showed a typical dictyostele pattern with variable number of leaf gaps, while roots of all the Pteris species were the diarch type with two xylem bundles alternating with two phloem bundles. The morphological and anatomical structures of the rhizomes and the roots provide useful specific distinctions of taxonomic importance for the genus Pteris and the family Pteridaceae.